(b) Description of the Related Art Generally, a fishway is provided at the side of a stream, enabling migrating fish to swim upstream and downstream around a dam or other obstruction.

When a sluice of the dam or other obstruction is opened, since a head of water is increased, increasing the speed of a current, it is difficult for the fishes to safely swim upstream. Therefore, there is a need for means that can retard the speed of a current when the sluice is opened.

A variety of fishways such as a waterway-type, a floodgate-type, and a piping-type are well known.

Korean Unexamined Utility Model No. 1999-0041787 and Korean Unexamined Patent No. 2001-0016199 disclose such means for retarding the speed of a current in the waterway-type fishway. U. S. Patent No.

4,629, 361 discloses a piping-type fishway system.

In the waterway-type fishway, to reduce the head of water, the fishway is made to be slowness. However, to make the fishway slowness,

the fishway should be designed be lengthened in a zigzag shape. However, as the structure is enlarged, the construction cost is increased.

In the case of the floodgate-type fishway, a floodgate, a power equipment, and workers for operating the power equipment are required, increasing the maintenance fees. Furthermore, it has an disadvantage of losing lots of water during the course of opening and closing the floodgate.

Enormous expense is also required to built the piping-type fishway as a lengthened pipe system arranged from a far upper stream to a far lower stream should be installed to retard the speed of a current.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the prior arts.

It is an objective of the present invention to provide a sluice system for a piping-type fishway that can a) be installed in a minimized size occupying a small space, b) allow pipe can be disposed in a variety of angles regardless and c) retard the speed of a current by providing a rotatable water wheel.

It is another objective of the present invention to provide a sluice system for a fishway that can enable for fishes to easily swim upstream by retarding the speed of a current.

In addition, it is another objective of the present invention to provide a sluice system for a fishway that can minimize the loss of the reserved water.

It is another objective of the present invention to provide a sluice system for a fishway, which can be driven by flowing water without using electric power source, thereby minimizing the maintenance fees.

To achieve the above objectives, the present invention provides a sluice system comprising a body having an inner space; an upper stream pipe for allowing water to flow into the inner space of the body; a lower stream pipe for discharging water from the main body; a fish compartment having a fish entrance, the fish compartment being rotatably disposed in the main body; a rotational drum disposed on an identical axis to that of the fish compartment to rotate together with the fish compartment; a water wheel connected to the rotational drum on an identical axis to that of the rotational drum to rotate together with the rotational drum; and upper and lower stream water wheel protecting members disposed in upper and lower connecting members, respectively.

When at least two water wheel are provided and the fish compartment is divided into at least two sub-compartments, the sub- compartments are separated by partitions and fish entrances of the sub- compartments are disposed to be offset from each other in a circumferential direction.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is an exploded perspective view of a sluice system for a fishway according to a preferred embodiment of the present invention; FIG. 2 is a front view of a sluice system according to a preferred embodiment of the present invention; FIG. 3 is a plan view of a sluice system according to a preferred

embodiment of the present invention; FIG. 4 is a perspective view of a rotational drum according to a preferred embodiment of the present invention; FIG. 5 is a side sectional view of FIG. 4; FIG. 6 is a side view of FIG. 4; FIG. 7 is a perspective view of a sluice system according to another preferred embodiment of the present invention; and FIG. 8 is a view illustrating a use example of a sluice system for a fishway piping system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described more in detail hereinafter in conjunction with the accompanying drawings.

FIG. 1 shows an exploded perspective view of a sluice system for a fishway according to a preferred embodiment of the present invention, FIG.

2 shows a front view of a sluice system according to a preferred embodiment of the present invention, FIG. 3 shows a plan view of a sluice system according to a preferred embodiment of the present invention, FIG.

4 shows a perspective view illustrating a perspective view of a rotational drum according to a preferred embodiment of the present invention, FI. G. 5 shows a side sectional view of FIG. 4, FIG. 6 shows a side view of FIG. 4, FIG. 7 shows a perspective view of a sluice system according to another preferred embodiment of the present invention, and FIG. 8 shows a view illustrating a use example of a sluice system for a fishway piping system of the present invention.

Referring to FIG. 8, a sluice system 10 of the present invention is

applied to a piping-type fishway system. The sluice system 10 is installed on a dam or other obstructions to selectively allow water in an upper stream reservoir 11 having a water lever 12 to flow downstream or supply the water to an intermediate reservoir 17 while retarding the speed of a current.

That is, an upper stream fishway pipe 13 of the sluice system 10 is connected to the upper stream reservoir 11. The flow of water in the upper stream fishway pipe 13 is controlled by a check valve 14. The upper stream fishway pipe 13 is connected to the intermediate reservoir 17 or the strip water of the lower streamside through a lower stream fishway pipe 15 of the sluice system 10.

The sluice system 10 comprises a main body 1 formed of a cylindrical single pipe, an upper stream connecting pipe 2a having an upper stream opening 3a and provided on an upper stream portion of the main body 1 and a lower stream connecting pipe 2a having a lower stream opening 3b and provided on a lower stream portion of the main body 1.

In addition, upper and lower water wheel protecting members 4a and 4b each having a width and a length for covering a water wheel 5 of a rotational drum 8 that will be described hereinbelow are installed in the upper and lower stream connecting pipes 2a and 2b at a position corresponding to the water wheel 5 of the rotational drum 8.

Each of the water wheel protecting members 4a and 4b are formed of a curved plate provided with plural apertures or of a curved mesh so as to allow the water to freely flow toward the water wheel while filtering alien substances and preventing fishes from advancing into the water wheel 5.

In addition, the rotational drum 8 is rotatably mounted in the main body 1. On a side of the rotation drum 8, a cylindrical fish compartment 6

having a fish entrance 7 is connected. The water wheel 5 is connected to the fish compartment 6. The water wheel 5 and the fish compartment 6 are disposed on an identical axis.

The rotational drum 8 is designed to rotate while maintaining a minimized gap between the upper and lower water wheel protecting members 4a and 4b.

Therefore, when water is flowed into the rotational drum 8 through a fishway pipe, the rotational drum 8 rotates as the water collides with the water wheel 5. At this point, the fish compartment also rotates to allow the fish entrance 7 to alternately communicate with the upper and lower stream connecting pipes 2a and 2b. As a result, the fishes coming in through the upper stream connecting pipe 2a swims into the fish compartment 6 through the fish entrance 7. In addition, when the fish entrance 7 communicates with the lower stream connecting pipe 2b as the rotational drum 8 rotates by 180°, the fishes swim downstream to the lower stream reservoir 17 through the lower stream connecting pipe 2b. It is also possible for the fishes to swim upstream.

The operation of the piping system of the present invention will be described more in detail in conjunction with the accompanying drawings.

As shown in FIGS. 1 to 8, the sluice system 1 is connected to the dam or other obstructions by the upper stream pipe 13. The upper stream reservoir 11 is connected to the lower stream strip water or the intermediate reservoir 17 through the lower stream pipe 15.

Furthermore, the water coming through the upper stream opening 3a is directed into the main body 1 through the upper stream connecting pipe 2a and the upper stream water wheel protecting member 4a. The water

directing into the main body 1 contacts the water wheel 5 of the rotational drum 8 to rotate the water wheel 5 at a predetermined rpm, thereby rotating the whole body of the rotational drum 8. Then, the water flows downstream the sluice system 10 after passing through the lower stream water wheel protecting member 4b, the lower stream connecting pipe 2b, and the lower stream opening 3b in this order.

Furthermore, as the water flowing into the sluice system 10 flows while filling the fish compartment and the main body, the fishes swimming downstream and upstream can stay in the main body 1. That is, the water filled in the fish compartment and the main body 1 functions as a kind of lure water luring the fishes into the fishway piping system.

When the rotational drum 8 rotates as described above, the water wheel 5 and the main body 1 should be designed each having a proper size so that the water wheel 5 can rotate at a proper rpm, whereby the fishes can easily swim into and out of the fish compartment 6.

Normally, when the water wheel 5 rotates at 2rpm, the fishes can easily swim. That is, the rpm is 2 and the size of the circular fish entrance 7 is 1/4, the fish entrance 7 is opened for 7.5 seconds, and then closed again for 7.5 seconds. That is, the opening time of the fish entrance 7 at the upper and lower portions of the sluice system 1 is actually of about 15 seconds. The fishes swim in and out of the fish compartment 6 for 15 seconds. Needless to say, when the rpm is 1, the fishes can easily swim in and out of the compartment.

In addition, to obtain the 2 rpm of the water wheel 5, the water level, the effective area of the upper stream water wheel protecting member, an amount of flowing water, a diameter and length of the water wheel, and a

speed of a current determined by a diameter and length of the main body proximal to the water wheel should be properly determined.

For example, when it is assumed that a water level difference between the upper and lower stream reservoirs is 4m, an inner diameter of the fish pipes 13 and 15 is 100cm, an inner diameter of the main body 1 is about 120cm, a diameter of the water wheel 5 is slightly less than 120 cm, a length of a water wheel blade is 40cm, and a length of the main body proximal to the water wheel is 70cm, 1) the circumferential length of the water wheel becomes L=s D (L: the length of the water wheel. D: the diameter of the water wheel) = 3. 14*120cm=377cm, 2) a speed of the water wheel (when the rpm is 2) becomes 2*377 cm/min, and a speed of a current around the water wheel becomes 754 cm/min, 3) a speed of a current passing through the upper stream water wheel protecting member becomes 51 2*g*h = | 2*10*4m/sec=8. 9m/sec = 8. 9*60m/min, 4) a flow retarding rate according to the Bernoulli theorem becomes M=V1*S1=V2*S2 (M: an amount of flowing water, V1 : a speed of a current passing through the upper stream water wheel protecting member, S1 : an effective sectional area of the opening of the upper stream water wheel protecting member, V2: a speed of a current around the water wheel, S2: an effective area of a waterway around the water wheel).

Therefore, to reduce the speed of a current around the water wheel to a predetermined rate, the effective sectional area of the opening should be reduced as the speed of a current passing through the upper stream water wheel protecting member is predetermined.

In the above, the sectional area S2 of the waterway is

S2=120cm*30cm=3600cnf. tn the formulae, 534*100cm/min*S1 is equal to 754cm/min*3600cm2. Therefore, the S1 becomes 50. 8cm2 = about 51 cnf.

As noted from the above results, when the effective sectional area of the opening of the upper stream water wheel protecting member is set to be less than 51ce2, the speed of a current around the water wheel becomes 754cni/min. the maximum rpm of the water wheel in theory becomes 2rpm.

As described above, by properly adjusting the sizes of the water wheel and the main body, the desired rotational speed of 2 rpm can be obtained. Since such speed can allow the fishes to swim upstream and downstream.

Meanwhile, the fishes advanced into the fishway piping system from the lower stream are further advanced into the fish compartment 6 through the lower stream opening 3b, the lower stream connecting pipe 2b, and the fish entrance 7 of the sluice system 10. At this point, since the fish compartment 6 is filled with the water, the fishes can stay in the fish compartment for a predetermined time.

In addition, when the fish compartment 6 rotates by 180° to reach the upper stream connecting pipe 2a, the fishes are advanced into the upper stream fishway pipe and then swim to the upper stream reservoir.

The swimming in the reverse direction to the above-described swimming of the fishes is also realized through the above-described procedure. That is, the fishes advanced into the fishway piping system from the upper stream are further advanced into the fish compartment 6 through the upper stream opening 3a, the upper stream connecting pipe 2a, and the fish entrance 7 of the sluice system 10. In addition, when the fish

compartment 6 rotates by 180° to reach the lower stream connecting pipe 2b, the fishes are advanced into the lower stream fishway pipe and then swim to the lower stream reservoir.

Alternatively, when the fish compartment 6 is divided into plural sub- compartment by partitions and each of the fish entrances 7 are formed to be offset from each other by 120° in a circumferential direction, since the fish entrance 7 looks like it is always opened when viewed from the lower streamside. That is, as the rotational drum 8 rotates, each of the fish entrances 7 consecutively communicates with the lower stream, it becomes easier for the fishes to swim upstream. Likewise, when viewed from the upper streamside, since the fish entrance 7 looks like to be always opened, it is also easy for the fishes to swim downstream.

In the above described sluice system, since the speed of a current is retarded and constantly maintained by the fishway piping system, the fishes can safely swim upstream and downstream. In addition, the amount of flowing water can be maintained constantly, the loss of the water can be minimized, thereby satisfying the water-reserving objection of a dam or other obstructions.

In addition, since the fishway piping system can be vertically mounted, and the sluice system can be mounted in any directions, the space can be saved, thereby reducing the construction costs.

Furthermore, as the fishway piping system is driven by flowing water, additional driving system is not required, thus saving the manufacturing costs and maintenance fees.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.